UGC NET - Ocean hazards: tsunamis and cyclone impacts on coasts. Online Test (MCQ Quiz)

1. What is the primary cause of most tsunamis?

A) Volcanic eruptions on the ocean floor B) Meteorite impacts in the ocean C) Underwater earthquakes D) Landslides into the ocean

2. Which seismic wave is most responsible for generating tsunamis?

A) P-waves (Primary waves) B) S-waves (Secondary waves) C) Surface waves D) Love waves

3. What is the typical wave height of a tsunami in the deep ocean?

A) Less than 1 meter B) Between 1 and 5 meters C) Between 5 and 10 meters D) More than 10 meters

4. As a tsunami approaches shallow coastal waters, what happens to its wave height and speed?

A) Wave height decreases, speed increases B) Wave height increases, speed decreases C) Wave height increases, speed increases D) Wave height decreases, speed decreases

5. Which ocean basin experiences the most frequent and significant tsunami activity?

A) Atlantic Ocean B) Indian Ocean C) Arctic Ocean D) Pacific Ocean

6. What is the term for the initial surge of water associated with a tsunami that moves inland?

A) Wave trough B) Wave crest C) Drawback D) Inundation

7. The 'Ring of Fire' is a region known for frequent earthquakes and volcanic activity. How does this relate to tsunamis?

A) It is a region where tsunamis are less likely to occur B) It is the primary source of tsunamis due to tectonic plate movement C) It influences tsunami direction but not generation D) It is related to atmospheric conditions affecting tsunamis

8. Which of the following is NOT a common impact of a tsunami on coastal environments?

A) Coastal erosion B) Salinization of soil and groundwater C) Increased biodiversity D) Destruction of infrastructure

9. What is the term used to describe the sudden withdrawal of the sea before a tsunami wave arrives?

A) Ebb tide B) Flood tide C) Drawback D) Surge

10. Which international warning system is designed to detect tsunamis and alert coastal communities?

A) NOAA Tsunami Warning System B) Pacific Tsunami Warning Center (PTWC) C) Indian Ocean Tsunami Warning System (IOTWS) D) All of the above

11. What is a 'cyclone' commonly known as in the North Atlantic and Northeast Pacific Oceans?

A) Typhoon B) Hurricane C) Tropical storm D) Willy-willy

12. What atmospheric condition is essential for the formation of tropical cyclones?

A) Cold ocean surface temperatures B) High atmospheric pressure C) Warm ocean surface temperatures (at least 26.5°C) D) Strong westerly winds

13. The 'eye' of a cyclone is characterized by:

A) The strongest winds and heaviest rainfall B) Calm conditions and clear skies C) Rapidly rising air pressure D) High humidity and dense clouds

14. What is the primary energy source that fuels a tropical cyclone?

A) Solar radiation B) Geothermal heat C) Latent heat released from condensation of water vapor D) Kinetic energy of prevailing winds

15. Which scale is commonly used to classify the intensity of hurricanes based on wind speed?

A) Richter Scale B) Saffir-Simpson Hurricane Wind Scale C) Torro Scale D) Beaufort Scale

16. What is 'storm surge' in the context of cyclones?

A) The rapid increase in air pressure B) A large wave generated by the cyclone's winds C) An abnormal rise of sea level and high tides D) The path of the cyclone across the ocean

17. Which of the following is a significant impact of cyclones on coastal areas?

A) Formation of new coral reefs B) Decreased coastal erosion C) Inundation and flooding due to storm surge D) Improvement of soil fertility

18. The Coriolis effect plays a crucial role in the rotation of cyclones. In which hemisphere do cyclones rotate clockwise?

A) Northern Hemisphere B) Southern Hemisphere C) Equatorial regions D) Both hemispheres rotate counter-clockwise

19. What is the term for a tropical cyclone that forms in the Northwest Pacific Ocean?

A) Cyclone B) Hurricane C) Typhoon D) Bagyo

20. Which of these factors exacerbates the impact of storm surges on coastlines?

A) Low tide conditions B) Steep continental shelf C) Mangrove forests and coastal wetlands D) High elevation of coastal land

21. The destructive power of a tsunami is primarily due to its:

A) High frequency and short wavelength B) Immense volume of water and momentum C) Low amplitude and long wavelength D) Rapid oscillation of water particles

22. Tsunami waves are often described as 'walls of water' because:

A) They break like typical ocean waves B) They carry debris and sediment C) They surge inland with significant force and height D) They are preceded by a distinct 'roar'

23. Geological evidence of past tsunamis on coastlines includes:

A) Accumulation of fine sand B) Uprooted trees and marine deposits inland C) Formation of sand dunes D) Erosion of bedrock

24. Which of the following coastal landforms offers the most natural protection against storm surges and tsunamis?

A) Sandy beaches B) Rocky cliffs C) Coral reefs D) Mangrove forests

25. The 'tsunami earthquake' is a term used for earthquakes that are particularly efficient at generating tsunamis. What characteristic do they typically possess?

A) Shallow focus and large magnitude B) Deep focus and small magnitude C) Strike-slip faulting D) High frequency seismic waves

26. Which type of fault movement is most likely to cause a tsunami?

A) Strike-slip fault B) Reverse fault (thrust fault) C) Normal fault D) Tensional fault

27. The energy of a tsunami wave is distributed throughout the entire water column, from the surface to the seafloor. This is a key difference from:

A) Wind-driven waves B) Tidal waves C) Rogue waves D) Seiches

28. What is the typical wavelength of a tsunami in the deep ocean?

A) Tens of meters B) Hundreds of meters C) Hundreds of kilometers D) Thousands of kilometers

29. The speed of a tsunami wave in the ocean is primarily determined by:

A) The wind speed B) The ocean depth C) The water temperature D) The salinity of the water

30. What is the term for the cyclical rise and fall of sea levels caused by the gravitational pull of the Moon and Sun?

A) Tsunami B) Tidal bore C) Tide D) Storm surge

31. A 'tsunami warning' typically indicates that:

A) A tsunami has been detected and is expected to impact the coast B) There is a potential for a tsunami C) Tsunami waves have already arrived D) The threat of a tsunami has passed

32. What is the term for a very large, destructive wave, often caused by factors other than seismic activity, such as underwater landslides or volcanic collapses?

A) Tidal wave B) Rogue wave C) Tsunami D) Seiche

33. The 'wave period' of a tsunami refers to:

A) The time it takes for one complete wave to pass a point B) The distance between two wave crests C) The height of the wave D) The speed of the wave

34. Which of the following impacts of cyclones is primarily related to changes in atmospheric pressure?

A) Heavy rainfall B) Strong winds C) Storm surge D) Lightning

35. The 'eyewall' of a cyclone contains:

A) The calmest weather B) The strongest winds and heaviest precipitation C) Relatively light winds D) The lowest atmospheric pressure

36. What is the main reason cyclones weaken when they move over land?

A) Increased atmospheric pressure B) Decreased sea surface temperatures C) Loss of their energy source (warm, moist air) D) Increased friction

37. Which of the following coastal features is most vulnerable to erosion by cyclone-induced waves and storm surge?

A) Large granite outcrops B) Steeply sloping bedrock C) Low-lying sandy barrier islands D) Elevated limestone plateaus

38. The 'wind shear' within a cyclone refers to:

A) The rotation of the storm B) The change in wind speed and/or direction with height C) The forward motion of the storm D) The pressure gradient within the storm

39. Which part of a cyclone is characterized by spiral bands of thunderstorms and heavy rain extending outwards from the center?

A) The eye B) The eyewall C) Rainbands D) The outflow

40. The devastating 2004 Indian Ocean tsunami was primarily triggered by an earthquake in which region?

A) The Mariana Trench B) The Sumatra-Andaman subduction zone C) The Japan Trench D) The Cascadia subduction zone

41. What impact can tsunamis have on freshwater resources near the coast?

A) Increased freshwater availability B) Salinization of groundwater and aquifers C) Reduced evaporation rates D) Increased rainfall

42. The term 'tsunami' is of Japanese origin, meaning:

A) Sea wave B) Harbor wave C) Ocean surge D) Earthquake wave

43. Which of the following is a long-term consequence of severe cyclone impacts on coastal ecosystems?

A) Rapid recovery of coral reefs B) Increased coastal vegetation density C) Habitat destruction and loss of biodiversity D) Expansion of coastal wetlands

44. What is the term for a localized, oscillating wave motion within a body of water, often caused by seismic activity or wind, that can be amplified in enclosed or semi-enclosed basins?

A) Tsunami B) Storm surge C) Tidal bore D) Seiche

45. The 'storm tide' is the combination of storm surge and:

A) Normal high tide B) Normal low tide C) Rainfall D) Wind speed

46. Which of the following is a critical component of effective tsunami preparedness in coastal communities?

A) Building structures close to the shoreline B) Ignoring evacuation orders C) Developing and practicing evacuation plans D) Relocating away from the coast permanently

47. What is the primary hazard associated with the 'eye' of a cyclone?

A) Extremely high winds B) Torrential rainfall C) Calm weather and potential for deceptive security D) Rapidly falling barometric pressure

48. The impact of a tsunami's 'drawback' refers to:

A) The initial surge of water inland B) The subsequent recession of water from the coast C) The breaking of the wave on the shore D) The formation of a bore

49. Which of the following is a significant socio-economic impact of both tsunamis and cyclones on coastal regions?

A) Increased tourism revenue B) Disruption of livelihoods and displacement of populations C) Improved agricultural yields D) Enhanced trade routes

50. What is the term for a rapid, wave-like surge of water that moves up a river or narrow bay, often caused by the incoming tide or a distant tsunami?

A) Storm surge B) Seiche C) Tidal bore D) Rip current

Ocean hazards: tsunamis and cyclone impacts on coasts. - Online Test

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